The Coalition is also bullish of snaring Lindsay in western Sydney. While Labor is unwilling to concede, there was little confidence of holding the seat.

Liberals also believe they will win back seats from independents, Wentworth in Sydney's eastern suburbs and Indi in rural Victoria but these could be offset by the potential defeat of Tony Abbott in Warringah as well as the return of independent Rob Oakeshott in Cowper.

As well as gains in Victoria, Labor anticipates picking up seats in Sydney and regional NSW, Brisbane and Perth, and believes it will stave off threats to Bass and Braddon in northern Tasmania.

Advertisement

"There is close to 20 seats where either side can win them," one senior Labor strategist told The Australian Financial Review.

"No one is going to know until the votes start coming in from 6pm on Saturday night."

Labor needs to win a net four seats to gain a gain a majority; or a uniform swing of 1 per cent, while the Coalition needs a net gain of three seats.

Two of the key seats that will determine the election are Reid in Sydney and Corangamite in regional Victoria.

Reid has become the most visited seat of the election, and Prime Minister Scott Morrison and Mr Shorten both campaigned there on Thursday in a strong indication it is on a knife edge, although a YouGov poll gave it 52-48 to the Liberals.

Labor's candidate for Reid, Sam Crosby, told the Financial Review he was feeling good as voters switched on.

"It is 4.7 per cent seat which means logically there are a dozen other ways you can form government without coming through Reid, but I think if you are winning Reid, you are winning government, so I want to do my bit," he said.

In Corangamite, Victorian Liberals credit incumbent MP Sarah Henderson for keeping the seat competitive this late in the campaign although some pessimism was creeping in on Thursday. "It is hard to see us finding the extra votes to win Corangamite," one Liberal source said.

Provided the government is re-elected, those promises will amount to the equivalent of $26,500 for each voter in the seat, seeing Mr Morrison dub the former ABC journalist "the most effective local member that Corangamite has ever seen".

"There is no tighter race than in Corangamite and every single vote will count," Ms Henderson said.

While no one was confident, Labor sources believed Corangamite would fall their way.

While there is a big swing on in Melbourne, it might not translate to a huge haul of seats. Polling shows an 8 per cent swing against Treasurer Josh Frydenberg in his safe seat of Kooyong and neighbouring Higgins remains in doubt, but the swing reaches far out from the CBD.

Polls in the Herald-Sun had the Liberals suffering a 6 per cent primary vote swing against them in Deakin, not enough to dislodge Michael Sukkar, while La Trobe, on Melbourne's urban fringe, was 50-50. A Labor source said while they thought they would win La Trobe, "I would like to be more confident at this stage".

The common view was that Queensland, with its eight Coalition marginal seats, was where the battle would be won and lost. So much so, that the Coalition based its campaign headquarters in Brisbane.

While both Mr Morrison and Mr Shorten made a dash there on Thursday night, the view is the Queensland will be like NSW on election day – swings and roundabouts.

Advertisement

A Nationals source believed the party's Ken O'Dowd would lose the regional seat of Flynn, despite a poll showing him ahead 53-47 on Thursday, while in Brisbane, Bonner and Forde, were likely to fall.

Despite expectations Herbert would change hands, Mr Morrison jetted into Townsville on Thursday night while a poll had it at 50-50.

Attention will be on Home Affairs Minister Peter Dutton, who instigated last year's leadership spill. Talk of Dickson falling has petered out, although one Liberal said there had been reports of queues for pre-polling in the seat, which they feared was not a good sign.

Getting these final few hundred votes in a raft of seats is proving hard going for Labor though, with a number of MPs having dug themselves in as local champions in tune with their constituents and capable of delivering taxpayer-funded projects. A poll in Forde showed it evenly split Thursday.

"Bert Van Manen is on 0.6 per cent [in Forde] but everyone loves Bert up there," the Labor strategist said.

In NSW, sources from both sides believed Labor would capture Gilmore. Recent internal polling had Labor and the Liberals neck and neck in the Central Coast seat of Robertson but Liberals were confident it would hold.

In Western Australia, both Labor and Liberal sources believe Swan and Stirling are the opposition's best chance of gaining seats.

Advertisement

While Labor is still spending money in Attorney-General Christian Porter's seat of Pearce, and Mr Shorten campaigned there on Wednesday, the Liberals believe ultimately he and fellow frontbencher Ken Wyatt would prevail.

"Everyone talks about we're going to lose Hasluck but we never do," one Liberal said.

Just as it thought at the start of the campaign, the Coalition believes it if can minimise losses in Victoria to Chisholm and Dunkley, it can win. This requires retaining the ultra-marginal Corangamite, which was rendered notionally Labor by the electoral redistribution.

Scott Morrison gets a welcome reception while campaigning at the Sydney markets in Reid on Thursday. Dominic Lorimer

The fight for Corangamite personifies the challenge facing Labor. They may have to look further up the pendulum for gains. Reid, in Sydney's inner west has become the most visited seat in the campaign, but has a margin of 4.7 per cent.

Traditionally volatile Tasmania remains a toss up in the northern seats of Bass and Braddon, where both leaders have campaigned this week, while the Coalition fancies its chances in Darwin-based Solomon.

A senior Coalition figure said Bass, with its 5.4 per cent margin, was in range for Liberal candidate and George Town mayor Bridget Archer, but votes would have to won person-by-person "away from the spotlight of the media and the national campaigns".

Several Labor and Coalition sources believed the opposition would finish with between 77 and 80 seats. Seventy-six is needed for majority government.

One Labor figure said even if the Opposition ended up with 74 seats, Mr Shorten would be in a strong position to negotiate with the Greens and Tasmanian independent Andrew Wilkie to form government.